DHT22/AM2302 Temp & Humidity Sensor

DHT22/AM2302 Sensor Digital Temperature And Humidity

Description DHT22/AM2302 Sensor 

• DHT22 utilizes exclusive digital signal collecting technique and humidity sensing technology and can ouptut calibrated digital signal.
• Small size & low consumption & long transmission distance (20 meters) enable AM2303 to be suited in all kinds of harsh applications.
•  When power is supplied to sensor don’t send any instruction to it withing one second to pass unstable status.
• It uses a capacitive humidity sensor and a thermistor to measure the surrounding air, and spits out a digital signal on the data pin.

• Connections are simple, the first pin on the left to 3-5V power, the second pin to your data input pin and the right most pin to ground.

  One 100nF capacitor can be added between VDD and GND for wave filtering.

  Technical details:

  • Power: 3-5V
  • Max Current: 2.5mA
  • Humidity: 0-100%, 2-5% accuracy
  • Temperature: -40 to 80°C, ±0.5°C accuracy

     http://playground.arduino.cc/Main/DHTLib

    Google for ‘DHT22 datasheet’ or ‘RHT03 datasheet’ for available datasheets

    download DHT22 datasheet

  DHT22 Module Pinout

  The diagram below shows the pinout of the DHT22 module.

  

  DHT22 Module Pinout (3-Pin Version)

  Pin Number	Pin Name	Function	Arduino Connection
  1	VCC	Power Supply (3.3V – 5V)	Arduino 5V or 3.3V
  2	DATA	Single-wire digital communication	Any digital pin (e.g., D2)
  3	GND	Ground reference	Arduino GND

  DATA Data Pin for 1-Wire Communication

  GND Ground Pin of the Module, Connects to the Ground pin of the Arduino.

  VCC Supply Pin of the Module.

  Not Used In this sensor, this pin is not used.

  DHT22 Bare Sensor Pinout (4-Pin Version)

  Important: The 4-pin DHT22 sensor includes an NC (Not Connected) pin. Always refer to the datasheet to identify the correct DATA pin position.

  Pin Position	Function	Note
  Pin 1	VCC (Power)	Connect to 3.3V or 5V
  Pin 2	DATA	Requires 10kΩ pull-up resistor
  Pin 3	NC (Not Connected)	Leave unconnected
  Pin 4	GND (Ground)	Connect to ground